Answer:
75 kgm/s
Explanation:
Impulse: This can be defined as the product of mass and change in velocity. The S.I unit is kgm/s.
From the question,
I = m(v-u)................... Equation 1
Where I = impulse, m = mass, v = final velocity, u = initial velocity.
Let the direction of the initial velocity be the positive direction.
Given: m = 5 kg, v = -10 m/s (bounce off), u = 5 m/s.
Substitute into equation 1
I = 5(-10-5)
I = 5(-15)
I = -75 kgm/s.
The negative sign tells that the impulse act in the same direction as the final velocity of the ball
Hence,
I = 75 kgm/s
Answer:
1065 Kgm-3
Explanation:
We can determine the relative density of the athlete from the formula;
Relative density of athlete = weight of athlete in air/upthrust on athlete
Since weight of athlete in air= 690 N
Weight of athlete in water = 42 N
Upthrust on athlete= weight in air - weight in water
Upthrust on athlete= 690 N - 42 N = 648 N
Relative density of athlete= 690 N / 648 N
Relative density of athlete= 1.065
Therefore, average density of the athlete= relative density × density of water = 1.065 × 1000 Kgm-3 = 1065 Kgm-3
Answer:
So option (a) is correct option
Explanation:
We have given final speed of the car = 23 m/sec
And initial speed of the car = 30 m/sec
Time in which speed is decreases t = 2 sec
From first equation of motion we know that v = u+at
So acceleration
Negative sign indicate that acceleration will be in opposite direction
So
So option (a) is correct option
Force on -7 uC charge due to charge placed at x = - 10cm
now we will have
towards left
similarly force due to -5 uC charge placed at x = 6 cm
now we will have
towards left
Now net force on 7 uC charge is given as
towards left
The angle that the boat must follow for it to be able to head upstream successfully should be 45 degrees from the current at which it is crossing. This is exact protocol that is done or learned by rescuers. In able to swim across a current, you must not invest your energy in heading towards it but rather move in a semi-perpendicular direction from it.