<span>According to Newton's first law of motion:
-- objects at rest will remain at rest unless acted upon by an outside force
-- objects in motion will remain in motion unless acted upon by an outside force
</span>
The rate of acceleration of the crate would be 1 m/s^2 because the equation for force is F=ma and when you plug in your numbers you get 10=10a so a=1
Answer:
W = F * s
Work done equals applied force * distance traveled
Apparent weight = M g (1 - sin θ) since some of applied force will lighten sled
μ = coefficient of kinetic friction
F cos θ = force applied to motion of sled
s = distance traveled
[μ M g (1 - sin θ)] cos θ * s = work done in moving sled
Note that F = μ M g if applied force is in the horizontal direction
a) 2.75 s
The vertical position of the ball at time t is given by the equation
where
h = 4 m is the initial height of the ball
u = 12 m/s is the initial velocity of the ball (upward)
g = 9.8 m/s^2 is the acceleration of gravity (downward)
We can find the time t at which the ball reaches the ground by substituting y=0 into the equation:
This is a second-order equation. By solving it for t, we find:
t = -0.30 s
t = 2.75 s
The first solution is negative, so we discard it; the second solution, t = 2.75 s, is the one we are looking for.
b) -15.0 m/s (downward)
The final velocity of the ball can be calculated by using the equation:
where
u = 12 m/s is the initial (upward) velocity
g = 9.8 m/s^2 is the acceleration of gravity (downward)
t is the time
By subsisuting t = 2.75 s, we find the velocity of the ball as it reaches the ground:
And the negative sign means the direction is downward.
The cost of boiling 500cm3 of water using the 3kW kettle is 1.35 P.
<h3>
Cost of electricity for 3 kW kettle</h3>
The cost is calculated as follows;
1 unit = 9p /kWh
Total energy consumed by 3 kW kettle, E = P x t
where;
- P is power (kW)
- t is time in (hr)
E = 3 kW x (3 mins/60 mins/hr)
E = 0.15 kWh
Energy cost = 9 p/kWh x 0.15 kWh = 1.35 P
Thus, the cost of boiling 500cm3 of water using the 3kW kettle is 1.35 P.
Learn more about energy cost here: brainly.com/question/13795167
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