Answer:
W = 1222.4 J = 1.22 KJ
Explanation:
The work done on an object is the product of the force applied on it and the displacement it covers as a result of this force. It must be noted that the component of displacement in the direction of force should only be used. Hence, the work can be calculated as:
W = F d Cosθ
where,
W = Work Done = ?
F = Force Applied = 64 N
d = Distance Covered by Box = 19.1 m
θ = Angle between force and displacement = 0°
Therefore,
W = (64 N)(19.1 m)Cos 0°
<u>W = 1222.4 J = 1.22 KJ</u>
D. convergent plate boundary involving an oceanic plate
U=10 m/s
v=30 m/s
t=6 sec
therefore, a=(v-u)/t
=(30-10)/6
=(10/3) ms^-2
now, displacement=ut+0.5*a*t^2
=60+ 0.5*(10/3)*36
=120 m
And you can solve it in another way:
v^2=u^2+2as
or, s=(v^2-u^2)/2a
=(900-100)/6.6666666.......
=120 m
Answer: 15m/s
Explanation: <u>Average</u> <u>Velocity</u> is vector describing the total displacement of an object and the time taken to change its position. It is represented as:

At t₁ = 1.0s, displacement x₁ is:

x(1) = 28
At t₂ = 4.0s:

x(4) = 73
Then, average speed is

v = 15
The average velocity of a car between t₁ = 1s and t₂ = 4s is 15m/s