Answer:
speed = distance/time
Explanation:
speed = 150/30
speed =5m/s
you were running fast .....5m/s is a good speed
Answer:
The work done on the sled by friction, W = - 4593.75 J
Explanation:
Given data,
The combined mass of sled and the boy, m = 75 kg
The displacement of the boy, S = 25 m
The coefficient of the friction, u = 0.25
The frictional force acting on the boy,
<em>F = u η</em>
Where,
η - is the normal force acting on the boy (mg)
Substituting the values,
F = 0.25 x 75 x 9.8
= 183.75 N
Since the direction of the frictional force is against the direction of motion
F = - 183.75 N
The work done on the sled by friction,
W = F x S
= - 183.75 x 25
= - 4593.75 J
Hence, the work done on the sled by friction, W = - 4593.75 J
Answer:
W = 112.58 N-unit
Explanation:
Given:
- Force F = 10 N
- Angle Q of force with x axis: 30 degrees
- distance to be moved d = 13 units along + x axis
Find:
Work Done by the force F:
Solution:
The work by force in positive x direction can only be done if the both the direction of distance traveled and direction of force are parallel vectors. Hence we compute the component of Force F in x direction F_x:
F_x = F*cos(Q)
F_x = 10*cos(30)
F_x = 8.66 N
Hence,
Work Done by force
W = F_x * d
W = 8.66 * 13
W = 112.58 N-unit