Physics Answers

A force of magnitude 7.50 N pushes three boxes with masses
m1 = 1.30 kg, m2 = 3.20 kg and m3 = 4.90 kg as shown in Figure 5–20. Find the magnitude of the contact force (a) between boxes 1 and 2, and (b) between boxes 2 and 3.

A boxer is working out on the heavy bag. On one of the boxer's punches the 41 kg heavy bag goes from hanging at rest to swinging at 6.59 m/s. The boxer's glove is in contact with the heavy bag for only 0.15 seconds.
With how much force, in N, does the boxer hit the heavy bag?

An athlete running at the velocity of 23m/s due east is confronted with two trade winds. One wind traveling at 10m/s in a direction of N65 degrees E and the other wind traveling at 8m/s in a direction S 70 degree E. Find the resultant velocity and direction of the athlete

1. A 10 kg sack of grain is hoisted to a storage room 50 m above the ground floor of a grain elevator.
a) What is the increase in potential energy of the sack of grain at this height? PE = mgh

A machine of efficiency 80% is used to raise a load of a body of mass 76kg through a vertical height of 3m in 30s. Calculate the power input (g=10ms²)

A body of mass 7.5kg is to be pulled up along a place which is included at 30° to the horizontal. If the efficiency of the place is 75%,what is the minimum force required to pull the body up the plane?

Measurement no Density (kg/m3
)
1 3.54
2 3.49
3 3.58
4 3.50
5 3.55
6 3.52
(i) Find average density.

1.Two spanners X and Y of lengths 15cm and 20cm respectively are used in turn to give a screw of pitch 2mm on e complete rotation. If Rx and Ry are the respective velocity ratios of the spinners,what is the velocity ratio of Rx to Ry.
2. The velocity ratio and efficiency of a system of pulley are 6 and 80% respectively. How much effort is required to lift a load of mass 120kg with this system?

. A diesel engine uses 54.5 kg of fuel oil per hour of calorific value 45 MJ/kg. The thermal efficiency of the engine is 25 per cent. Determine the power output of the engine in kilowatts

Discuss the various types of microwave horn antennae on the basis of their construction, directivity and applications.