Mechanics | Relativity Answers

If you exert 12.6 N for a distance of 2.4 m in 1.5 s, you will deliver a power of __W, N

a force applied on a body of1.2kg for 0.2 s and the body travelled a distance of 2m in the next round. Find the force applied on th body.

You drop a rock from rest off a cliff, and it hits the ground 8.1 seconds later. How tall is the cliff？

A ball of density "ρ" is dropped from a vertical cliff of height "h" with zero initial velocity. Now it penetrates through water and reach back its surface
Calculate the total time taken. (Note thah "ρ" is less than water density)

If the roller coaster car in the above problem were moving with twic(40.0m/s)the speed,then what would be its new kinetic energy

1. Ahmad is driving North on Highway 69 at 90 km/h and sees a large moose on the road. He quickly slams on his brakes, but his reaction time is 0.85 s (as he sees the moose, thinks about his response, and then presses the brake pedal). He presses the brake for 3.5 s and comes to a stop just in time.
a) Find the distance travelled after seeing the moose and before pressing the brake.

Calculate the distance an arrow will land from a hunter if he releases the arrow
with a speed of 20m/s at a 60 degree angle above the horizontal. The tip of the
arrow is 1.5 m above the ground at the point of release.

6.) A meter stick of uniform density is balanced horizontally on a fulcrum with support at its center of mass (i.e. the 50 cm mark). A weight is hung at the 35 cm mark and the meterstick begins to rotate with an angular acceleration of 0.20 rad/s^2. Given that the moment of inertia of the meterstick is (1/12)*M*L^2 and the mass M of the meter stick is 0.12 kg A) What is the torque on the meter stick?
B.) What is the amount of weight hung at the 35 cm mark?
C.) Does the torque increase, decrease or remain constant as the meter stick begins to rotate?

Johnny Quest is a boy of mass 70 kg. He is standing on a diving board bent 50 cm down and of stiffness 20 kN/m and he is 5 m high above the tranquil waters of the blue lagoon. He is flung into the air by the diving board towards the top of a coconut tree. If he lands at a speed of 3 m/s then find the height of the tree. Assume he does not lose any energy as heat due to drag – the drag is negligible and the efficiency is 100%.

We know that Kinetic energy is directly proportional to the square of velocity
And square of velocity is inversely proportional to mass. Therefore, shouldn't the mass be inversely proportional to kinetic energy?