Answer:
1.56 J
Explanation:
given,
Spring compression, x = 2.5 cm
Force exerts by the spring,
F = - k x
k = 5000 N/m
Potential energy stored = ?
energy stored in the spring
PE = 1.56 J
Hence, the potential energy stored in the car is equal to 1.56 J.
Answer:
Explanation:
The distance between successive wave crests at sea is 20 m. The boat descends from the crest of the wave, rises and reaches the highest position again within 5 s. Calculate the wave propagation speed.
Given that,
The distance between two successive crest is 20m
Wavelength is the distance between two successive crest or trough
Then, it's wavelength is λ = 20m
The time to reached the maximum height is 5seconds, then it will take (5×4) to complete one period
Then,
Period T = 20seconds
From wave equation
v = fλ
Where
v is speed
f is frequency and
λ is wavelength
The frequency is related to the period
f = 1 / T
Then,
v = λ / T
So, v = 20 / 20
v = 1 m/s
The speed of propagation of the wave is 1m/s
To Polish
Jeśli się uwzględni,
Odległość między dwoma kolejnymi grzebieniami wynosi 20 m
Długość fali to odległość między dwoma kolejnymi grzebieniami lub dolinami
Zatem jego długość fali wynosi λ = 20 m
Czas do osiągnięcia maksymalnej wysokości wynosi 5 sekund, a następnie ukończenie jednego okresu zajmie (5 × 4)
Następnie,
Okres T = 20 sekund
Z równania falowego
v = fλ
Gdzie
v to prędkość
f oznacza częstotliwość, a
λ jest długością fali
Częstotliwość jest związana z okresem
f = 1 / T
Następnie,
v = λ / T
Zatem v = 20/20
v = 1 m / s
Prędkość propagacji fali wynosi 1m/s
Explanation:
Given that,
Force with which a child hits a ball is 350 N
Time of contact is 0.12 s
We need to find the impulse received by the ball. The impulse delivered is given by :
So, the impulse is 42 N-m..
We know that he change in momentum is also equal to the impulse delivered.
So, impulse = 42 N-m and change in momentum =42 N-m.