Answer:
A. W = 6875.0 J.
B. W = -14264.6 J.
Explanation:
A. The work done by the rider can be calculated by using the following equation:
Where:
: is the force done by the rider = 25 N
d: is the distance = 275 m
θ: is the angle between the applied force and the distance
Since the applied force is in the same direction of the motion, the angle is zero.
Hence, the rider does a work of 6875.0 J on the bike.
B. The work done by the force of gravity on the bike is the following:
The force of gravity is given by the weight of the bike.
And the angle between the force of gravity and the direction of motion is 180°.
The minus sign is because the force of gravity is in the opposite direction to the motion direction.
Therefore, the magnitude of the work done by the force of gravity on the bike is 14264.6 J.
I hope it helps you!
Given that.
F=3•i+4•j
And it from point (0,0)m to (5,6)m
dx=final position - initial position
dx=(5,6)-(0,0)
dx=(5,6)m
dx=5•i +6•j
Work done by the force is give by
W = F•dx
W=F•dx
Note that i•i=j•j=1 and i•j=j•i=0
Then,
W=(3i+4j)•(5i+6j)
Therefore,
W=3i•(5i+6j)+4j•(5i+6j)
W=15i•i+18i•j+20j•i+24j•j
W=15+0+0+24
W=39J
Then the work done by the force is 39 Joules
To solve this problem we will apply the energy conservation theorem for which the work applied on a body must be equivalent to the kinetic energy of this (or vice versa) therefore
Here,
m = mass
= Velocity (Final and initial)
First case) When the particle goes from 10m/s to 20m/s
Second case) When the particle goes from 20m/s to 30m/s
As the mass of the particle is the same, we conclude that more energy is required in the second case than in the first, therefore the correct answer is A.
5 is the minimum number of cycles necessary for the engine to lift a rock of mass 570 kg
The statement ‘The three major scales used to measure
earthquakes are Mercalli Scale, Richter Scale and Magnitude Scale’ is true. These
three scales used to measure the seismic waves released by the earthquake.
