Mechanics questions | form five Physics

Find both graphically and by calculating, the horizontal and vertical components of a force of 50N which is acting at 40° to the horizontal.

The horizontal and vertical components of a force are respectively 20 N and 30 N. Calculate the magnitude and direction of the force.

Raindrops of mass fall vertically in still air with a uniform speed of 3ms^-1.If such drops are falling when a wind is blowing with a speed of 2ms^-1, what is the angle which the paths of the drops make with the vertical ? What is the kinetic energy of a drop?

A ship initially at rest accelerates steadily on a perfect smooth sea. How would you attempt to estimate the value of the acceleration from within the ship? You cannot see out, but you have available all the apparatus normally found in a school laboratory.(You may assume that the acceleration is not less than 1ms^-1.)

A light string carrying a small bob of mass hangs from the roof of a moving vehicle.

1. What can be said about the motion of the vehicle if the string hangs vertically?
2. The vehicle moves in a horizontal straight line from left to right, with a constant acceleration of 2.0ms^-2.

1. Show in a sketch the forces acting on the bob
2. By resolving horizontally and vertically or by scale drawing , determine the angle which the string makes with the vertical.

100. The vehicle moves down an incline making an angle 30° with the horizontal with a constant acceleration of 3.0ms^-2. Determine the angle which the string makes with the vertical.

A hose with a nozzle 80mm diameter ejects a horizontal stream of water at a rate of . With what velocity will the water leave the nozzle?. What will be the force exerted on a vertical wall situated close to the nozzle and at right-angles to the stream of water, if, after hitting the wall.

1. The water falls vertically to the ground
2. The water rebounds horizontally?

(Density of water =1000kg m^-3)

What is the connection between force and momentum? A helicopter of total mass 1000kg ia able to remain in a stationary position by imparting a uniform downward velocity to a cylinder of air below it of effective diameter 6m. Assuming the density of air to be , calculate the downward velocity given to the air.

An astronaut is outside her space capsule in a region where the effect of gravity can be neglected. She uses a gas gun to move herself relative to the capsule. The gas gun fires gas from a muzzle of area 160mm² at a speed of 150ms^-1 . The density of the gas is 0.800 kg m^-3 and the mass of the astronaut , including her space suit , is 130 kg. Calculate:

1. The mass of gas leaving the gun per second
2. The acceleration of the astronaut due to the gun, assuming that the change in mass is negligible

Sand is poured at a steady rate of on to the pan of a direct reading balance calibrated in grams. If the sand falls from a height of 0.20 m on to the pan and it does not bounce off the pan then, neglecting any motion of the pan, calculate the reading on the balance 10 seconds after the sand first hits the pan.

A pebble is dropped  from rest at the top of a cliff 125m high. How long does it take to reach the foot of the cliff, and with what speed does it strike the ground? With what speed must a second pebble be thrown vertically down-wards from the cliff top if it is to reach the bottom in 4 seconds?(Ignoring resistance of air)