Answer:
1. 3 m
2. 27 s
Explanation:
1. "A car traveling at +33 m/s sees a red light and has to stop. If the driver can accelerate at -5.5 m/s², how far does it travel?"
Given:
v₀ = 33 m/s
v = 0 m/s
a = -5.5 m/s²
Unknown: Δx
To determine the equation you need, look for which variable you don't have and aren't solving for. In this case, we aren't given time and aren't solving for time. So look for an equation that doesn't have t in it.
Equation: v² = v₀² + 2aΔx
Substitute and solve:
(0 m/s)² = (33 m/s)² + 2(-5.5 m/s²) Δx
Δx = 3 m
2. "A plane starting from rest at one end of a runway accelerates at 4.8 m/s² for 1800 m. How long did it take to accelerate?"
Given:
v₀ = 0 m/s
a = 4.8 m/s²
Δx = 1800 m
Unknown: t
Equation: Δx = v₀ t + ½ a t²
Substitute and solve:
1800 m = (0 m/s) t + ½ (4.8 m/s²) t²
t ≈ 27 s
Answer:280.216j/kg°C
Explanation:
Mass of metal=0.0663kg
mass of water=0.395kg
Final temperature=27.4°C
Temperature of metal=241°C
Temperature of water=25°C
specific heat capacity of water=4186j/kg°C
0.0663xax(241-27.4)=0.395x4186x(27.4-25)
0.0663xax213.6=0.395x4186x2.4
14.16168a=3968.328
a=3968.328 ➗ 14.16168
a=280.216j/kg°C
Answer:
14523.55J
Explanation:
The work done by the jogger against gravity is given by the following equation;
where m is the mass, g is acceleration due to gravity taken as 
and h is the height of the hill.
Since the length of the hill is 132m and it is inclined at 12 degrees to the horizontal, the height is thus given as follows;
Substituting this into equation (1) with all other necessary parameters, we obtain the following;
The combined amount of kinetic and potential energy of its molecules
