Answer:
F = 1.68 N
Explanation:
Let's solve this exercise in parts.
Let's use the concept of conservation of the mechanical nerve
initial
Em₀ = 500 J
The energy is totally kinetic
Em₀ = K = ½ m v₀²
v₀ =
v₀ = √ (2 500/32)
v₀ = 5.59 m / s
now with kinematics we can find a space
v² = v₀² - 2 a x
the negative sign is because the body is stopping
a =
let's calculate
a = (5.59² - 5.1²) / 2 50
a = 0.0524 m / s²
Finally let's use Newton's second law
F = ma
F = 32 0.0524
F = 1.68 N
Answer:
104.6 m
Explanation:
The motion of the car is a projectile motion, consisting of:
- A horizontal motion at constant speed
- A vertical motion at constant acceleration (acceleration of gravity)
We know that:
The initial horizontal velocity of the car is , and this is constant during the entire motion, as there are no forces in the horizontal direction
is the horizontal distance travelled by the car
Therefore, we can find the total time of flight of the car:
Now we analyze the vertical motion, which is a free fall motion, so we can use the suvat equation:
where
s is the vertical displacement (= the height of the cliff)
u = 0 is the initial vertical velocity
t = 4.62 s is the time of flight
is the acceleration of gravity
Solving for s, we find the height of the cliff:
Answer:
180 m
Explanation:
Given:
Uniform speed of the car, U = 30 m/s
Uniform acceleration of the motorcycle = 10 m/s²
For the motorcycle to catch up with the car, the distance traveled must be the same.
For the car;
Distance = Speed × Time
⇒ d = u × t
d = 30 × t
d = 30t ......(1)
For the motorcycle;
The stationary police motorcycle has initial speed, u = 0
From equation of motion;
but u = 0
.....(2)
Equating equation (1) and (2)
30t = 5t²
t = 6 seconds
Substituting t = 6 s into equation (2)
d = 5(6)²
d = 5 × 36
d = 180 m
The motorcycle must travel 180 m before it catches up to the car