143720 A train travels east towards Hubli at \(80 \mathrm{~km} / \mathrm{h}\). A man on the train runs from the front of the train toward the rear of the train at \(10 \mathrm{~km} / \mathrm{h}\) with respect to train. As he runs, he carries a plate of fruit with him. He notices a giant spider on the plate and throws the plate away from him (toward the rear of the train) at 20 \(\mathrm{km} / \mathrm{h}\) with respect to him. Just after that instant, the startled spider jumps towards the man at \(5 \mathrm{~km} / \mathrm{h}\) with respect to plate. The instant after the spider jumps toward the man, how fast is the spider approaching Hubli?
143721 A boat crosses a river from port \(A\) to port \(B\), which are just on the opposite side. The speed of the water is \(v_{w}\) and that of boat is \(v_{B}\) relative to still water. Assume \(v_{B}=2 v_{w}\). What is the time taken by the boat, if it has to cross the river directly on the \(A B\) line \([D=\) width of the river]
143722 A passenger in a open car travelling at \(30 \mathrm{~m} / \mathrm{s}\) throws a ball out over the bonnet. Relative to the car the initial velocity of the ball is \(20 \mathrm{~m} / \mathrm{s}\) at \(60^{\circ}\) to the horizontal. The angle of projection of the ball with respect to the horizontal road will be
143720 A train travels east towards Hubli at \(80 \mathrm{~km} / \mathrm{h}\). A man on the train runs from the front of the train toward the rear of the train at \(10 \mathrm{~km} / \mathrm{h}\) with respect to train. As he runs, he carries a plate of fruit with him. He notices a giant spider on the plate and throws the plate away from him (toward the rear of the train) at 20 \(\mathrm{km} / \mathrm{h}\) with respect to him. Just after that instant, the startled spider jumps towards the man at \(5 \mathrm{~km} / \mathrm{h}\) with respect to plate. The instant after the spider jumps toward the man, how fast is the spider approaching Hubli?
143721 A boat crosses a river from port \(A\) to port \(B\), which are just on the opposite side. The speed of the water is \(v_{w}\) and that of boat is \(v_{B}\) relative to still water. Assume \(v_{B}=2 v_{w}\). What is the time taken by the boat, if it has to cross the river directly on the \(A B\) line \([D=\) width of the river]
143722 A passenger in a open car travelling at \(30 \mathrm{~m} / \mathrm{s}\) throws a ball out over the bonnet. Relative to the car the initial velocity of the ball is \(20 \mathrm{~m} / \mathrm{s}\) at \(60^{\circ}\) to the horizontal. The angle of projection of the ball with respect to the horizontal road will be
143720 A train travels east towards Hubli at \(80 \mathrm{~km} / \mathrm{h}\). A man on the train runs from the front of the train toward the rear of the train at \(10 \mathrm{~km} / \mathrm{h}\) with respect to train. As he runs, he carries a plate of fruit with him. He notices a giant spider on the plate and throws the plate away from him (toward the rear of the train) at 20 \(\mathrm{km} / \mathrm{h}\) with respect to him. Just after that instant, the startled spider jumps towards the man at \(5 \mathrm{~km} / \mathrm{h}\) with respect to plate. The instant after the spider jumps toward the man, how fast is the spider approaching Hubli?
143721 A boat crosses a river from port \(A\) to port \(B\), which are just on the opposite side. The speed of the water is \(v_{w}\) and that of boat is \(v_{B}\) relative to still water. Assume \(v_{B}=2 v_{w}\). What is the time taken by the boat, if it has to cross the river directly on the \(A B\) line \([D=\) width of the river]
143722 A passenger in a open car travelling at \(30 \mathrm{~m} / \mathrm{s}\) throws a ball out over the bonnet. Relative to the car the initial velocity of the ball is \(20 \mathrm{~m} / \mathrm{s}\) at \(60^{\circ}\) to the horizontal. The angle of projection of the ball with respect to the horizontal road will be
143720 A train travels east towards Hubli at \(80 \mathrm{~km} / \mathrm{h}\). A man on the train runs from the front of the train toward the rear of the train at \(10 \mathrm{~km} / \mathrm{h}\) with respect to train. As he runs, he carries a plate of fruit with him. He notices a giant spider on the plate and throws the plate away from him (toward the rear of the train) at 20 \(\mathrm{km} / \mathrm{h}\) with respect to him. Just after that instant, the startled spider jumps towards the man at \(5 \mathrm{~km} / \mathrm{h}\) with respect to plate. The instant after the spider jumps toward the man, how fast is the spider approaching Hubli?
143721 A boat crosses a river from port \(A\) to port \(B\), which are just on the opposite side. The speed of the water is \(v_{w}\) and that of boat is \(v_{B}\) relative to still water. Assume \(v_{B}=2 v_{w}\). What is the time taken by the boat, if it has to cross the river directly on the \(A B\) line \([D=\) width of the river]
143722 A passenger in a open car travelling at \(30 \mathrm{~m} / \mathrm{s}\) throws a ball out over the bonnet. Relative to the car the initial velocity of the ball is \(20 \mathrm{~m} / \mathrm{s}\) at \(60^{\circ}\) to the horizontal. The angle of projection of the ball with respect to the horizontal road will be