Answer:
The vector magnitudes F and r are always postive, so the sign o W is determined entirely by the angle e between the force and the displacement.Submit Figure 1 off 1 part C
Answer:
Explanation:
a) The magnitude of the net force on the student = 0 N since the student is standing still on level ground and upward reaction force = downward force.
b) the magnitude of the contact force on the student by the backpack = 80 N since the student was backing the backpack
c) the magnitude of the contact force o the student by the ground = 550 N + 80 N = 630 N reactional force on the student
Q: ken, 0.75 kg, moves toward a wall (his path normal to the wall) at 52 m/s. 13.0 ms after he touches the wall he pushes himself off in the opposite direction at 60 m/s. What is the magnitude of the average force the wall exerts on Ken during this rapid maneuver
Answer:
-6461.54 N
Explanation:
From Newton's Fundamental equation,
F = m(v-u)/t.................... Equation 1
Where F = Force exerted in sonic, m = mass of ken, v = final velocity, u = initial velocity, t = time.
Given: m = 0.75 kg, v = - 60 m/s (opposite direction), u = 52 m/s, t = 13 ms = 0.013 s
Substitute into equation 1
F = 0.75(-60-52)/0.013
F = 0.75(-112)/0.013
F = -84/0.013
F = -6461.54 N
Note: The negative sign tells that the force act in opposite direction to the initial motion of ken.
Hence the magnitude of the average force of the wall = -6461.54 N
The same bird on the tree has more gravitational potential energy. This is because it is at a higher distance from the ground as it is on the tree, than when it is on the ground.
Considering also the formula for Gravitational Potential Energy GPE = mgh
For the bird on the ground, h =0, therefore GPE = m*9.8*0 = 0
For that on the tree = mgh = m*9.8*h
Of course the one on the tree has a value greater than zero.
779,247 J is the amount of heat released.
<u>Explanation:</u>
The equation that gives the amount of heat supplied is
Where,
E or Q – amount of heat supplied
m- mass
- specific heat capacity of Aluminium
– temperature variation caused by heat change
The amount of heat energies that causes the temperature to vary 
or 1 K per kg of the material is known as specific heat capacity (c)
Here, Given data:
– 0.900 J/g.K
To convert gram into kilogram, multiply and divide by 
, we get
Specific heat capacity of aluminum = 900 J/kg. K
m – 5.89 kg
By substituting the known values in the above equation, we get
