Answer:
The final velocity of the car is 36 m/s.
Explanation:
Given;
initial velocity of the car, u = 20 m/s
time of the car acceleration, t = 4 s
acceleration of the car, a = 4 m/s²
the final velocity of the car is calculated as;
v = u + at
where;
v is the final velocity of the car
v = 20 + (4 x 4)
v = 36 m/s
Therefore, the final velocity of the car is 36 m/s.
Radio waves are what cell phone company rely on
Answer:
20.42 N/m
Explanation:
From hook's law,
F = ke ......................... Equation 1
Where F = Force applied to the spring., k = spring constant, e = extension.
Make k the subject of the equation,
k = F/e ................. Equation 2
Note: The force on the spring is equal to the weight of the mass hung on it.
F = W = mg.
k = mg/e................ Equation 3
Given: m = 250 g = 0.25 kg, e = 37-25 = 12 cm = 0.12 m.
Constant: g = 9.8 m/s²
Substitute into equation 3
k = (0.25×9.8)/0.12
k = 20.42 N/m.
Hence the spring constant = 20.42 N/m