Answer:
ΔL = 3.82 10⁻⁴ m
Explanation:
This is a thermal expansion exercise
ΔL = α L₀ ΔT
ΔT = T_f - T₀
where ΔL is the change in length and ΔT is the change in temperature
Let's reduce the length to SI units
L₀ = 90.5 mm (1m / 1000 mm) = 0.0905 m
let's calculate
ΔL = 25.10⁻⁶ 0.0905 (154.6 - (14.4))
ΔL = 3.8236 10⁻⁴ m
using the criterion of three significant figures
ΔL = 3.82 10⁻⁴ m
Answer:
a) 19440 km/h²
b) 10 sec
Explanation:
v₀ = initial velocity of the car = 45 km/h
v = final velocity achieved by the car = 99 km/h
d = distance traveled by the car while accelerating = 0.2 km
a = acceleration of the car
Using the kinematics equation
v² = v₀² + 2 a d
99² = 45² + 2 a (0.2)
a = 19440 km/h²
b)
t = time required to reach the final velocity
Using the kinematics equation
v = v₀ + a t
99 = 45 + (19440) t
t = 0.00278 h
t = 0.00278 x 3600 sec
t = 10 sec
Answer:In the case of burning wood, stored potential energy (in the form of chemical energy) in the log is released due to heating by other excited atoms. This chemical reaction is called combustion and requires oxygen. Combustion changes the potential chemical energy into kinetic energy in the form of heat.
Explanation:
The force is -12,000 N
Explanation:
First of all, we calculate the acceleration of the ball, by using the following suvat equation:
where:
v = 0 is the final velocity of the baseball (it comes to rest)
u = 40 m/s is the initial velocity
a is the acceleration
s = 2.0 cm = 0.02 m is the displacement of the ball
Solving for a,
Now we can calculate the average force exerted on the ball, by using Newton's second law:
where
m = 300 g = 0.3 kg is the mass of the ball
is the acceleration
Substituting,
where the negative sign indicates that the direction of the force is opposite to the direction of motion of the ball.
Learn more about forces:
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Answer:
Explanation:
F = Magnetic force = 0.018 N
B = Magnetic field = 0.03 T
L = Length of wire = 35 cm
= Angle between current and magnetic field = 
Magnetic force is given by
The magnitude of the current is .
