A block of mass $$m = 2.50 kg$$ is pushed a distance $$d = 2.20 m$$ along a frictionless, horizontal table by a constant applied force of magnitude $$F = 16.0 N$$ directed at an angle $$\theta = 25.0^{0}$$ below the horizontal as shown in above figure. Determine the work done on the block by (a) the applied force, (b) the normal force exerted by the table, (c) the gravitational force, and (d) the net force on the block.

Verified by Toppr

We apply the definition of work by a constant force in the first three parts, but then in the fourth part we add up the answers. The total (net) work is the sum of the amounts of work done by the individual forces, and is the work done by the total (net) force. This identification is not represented by an equation in the chapter text, but is something you know by thinking about it, without relying on an equation in a list.
The definition of work by a constant force is $$W = FΔr \cosθ$$.
(a) The applied force does work given by
$$W = FΔr \cosθ = (16.0 N)(2.20 m)\cos25.0^{0} = 31.9 J$$
(b), (c) The normal force and the weight are both at $$90^{0}$$ to the displacement in any time interval. Both do $$0$$ work.
(d) $$\sum W = 31.9 J + 0 + 0 = 31.9 J$$

Was this answer helpful?
Similar Questions

A block of mass m is pushed by applying a force F at an angle θ with the horizontal surface. The normal force on the block is given as -

View Solution

A block of mass M is pulled along a horizontal frictionless suface by a rope of mass m. If a force F is applied at the free end of the rope, the net force exerted on the block will be

View Solution

Two blocks, A and B, of masses 8 kg and 2 kg, respectively, lie on a horizontal frictionless surface as shown in the figure. They are pushed by a horizontally applied force of 15 N. The force exerted by B on A is:​

View Solution

A block of mass M is pulled along a horizontal surface by applying a force at an angle θ with horizontal. Coefficient of friction between block and surface is μ. If the block travels with uniform velocity, find the work done by this applied force during a displacement d of the block.

View Solution

If a pushing force an angle α with horizontal is applied on a block of mass m placed on horizontal table and angle of function is β, then minimum magnitude of force required to move the block is

View Solution