Mechanics | Relativity Answers

A beam of uniform rectangular section 100 mm wide and 240 mm deep is simply supported at its ends. It carries a uniformly distributed load of 9.125 KN/m run over the entire span of 4m. Find the deflection at the centre of E= 1.1×10^4 N/mm^2

If the distance of an object is 23 cm in the focal length is -7 what is the distance of the image

(P+a/V) (V-b) = RT

What is the work done by gravity when a wooden block of mass 2 kg slides 3 m down a slope inclined at 30°?

A. 3 J

B. 29.43 J

C. 6 J

D. 58.86 J

A rock is thrown off the cliff horizontally with the speed of v = 12 m/s. The cliff is h=47 meter high. Find the speed of the rock once it hits the water in m/s. Give your answer with one decimal place.

A stone is thrown from a point A with speed 27 m/s at an angle of 26 degree below the horizontal. The point A is 25 m above the horizontal ground. Find the horizontal range of the stone in meter. Give your answer with one decimal place.

A mass of 20 kg is being pulled, with a rope, up a frictionless slope inclined at an angle of 30°. The rope is parallel to the slope, and the mass is traveling at a constant 5 ms-1 in a straight line.

a. Draw a free-body diagram for this situation.

b. Draw a vector triangle for the weight, dividing it into perpendicular components.

c. Calculate the component of the weight that is parallel to the slope.

d. Hence calculate the work done in pulling the mass 3 metres.

e. What is the power required?

f. How much gravitational potential energy has the mass gained when pulled 3 metres along the slope?

g. The 20 kg mass is then released from rest on another 30° slope, but this time there is a frictional force of 15 N. Find the magnitude and direction of the acceleration in this case.

A boy has a mass of 50 kg. He jumps at a speed of 2.5 m/s into a stationary boat which has a mass of 70 kg. Please calculate their speed (ignore friction).

Pumped-storage hydroelectricity allows energy to be stored to prepare for periods of high demand. Let a high-level reservoir be 500 m above a low-level reservoir. What is the useful power output if the water from the high-level reservoir flows at a rate of 100 kg per minute and the turbine is 85% efficient?

1.     A truck moving at 35 m/s collide with a car moving at 50 m/s. After collision, both truck and car move together at the same speed. Mass of the truck is 1,500 kg and the mass of the car is 700 kg. What is the velocity of both truck and car after collision?