Look at the diagram below. What is the size of the overall force on the boat?

A car accelerates uniformly in a straight line

julia-pushkina [17]

The car travels a distance d from rest with acceleration a after time t of

d = 1/2 a t²

It covers 69 m with 2.8 m/s² acceleration, so that

69 m = 1/2 (2.8 m/s²) t²

t² = 2 (69 m) / (2.8 m/s²)

t ≈ 7.02 s

where we take the positive square root because we're talking about time *after* the car begins accelerating.

8 0

3 years ago

A 0.473 kg ice puck, moving east with a speed of 2.76 m/s, has a head-on collision with a 0.819 kg puck initially at rest. Assum

Gekata [30.6K]

Answer:

The final speed of puck 1 is 0.739 m/s towards west and puck 2 is 2.02 m/s towards east .

Explanation:

Let us consider east as positive direction and west as negative direction .

Given

mass of puck 1 , $m_1= 0.473 kg$

mass of puck 2 , $m_2= 0.819 kg$

initial speed of puck 1 , $u_1=2.76\frac{m}{s}$

initial speed of puck 2 , $u_2=0.00\frac{m}{s}$

Final speed of puck 1 and puck 2 be $v_1\, and\, v_2$ respectively

Apply conservation of linear momentum

$m_1u_1+m_2u_2=m_1v_1+m_2v_2$

=> $0.473\times 2.76+0.0=0.473\times v_1+0.819\times v_2$

=> $1.594=0.5775\times v_1+ v_2$ -----(A)

Since collision is perfectly elastic , coefficient restitution e=1

$u_2-u_1=v_1-v_2$

=> $0-2.76=v_1-v_2$ ------(B)

From equation (A) and (B)

$v_1=-0.739\frac{m}{s}$

and $v_2=2.02\frac{m}{s}$

Thus the final speed of puck 1 is 0.739 m/s towards west and puck 2 is 2.02 m/s towards east .

3 0

3 years ago

Two vectors are being added, one at an angle of 20.0 , and the other at 80.0. The only thing you know about the magnitudes is th

postnew [5]

Answer:a

Explanation: they are all positive

4 0

2 years ago

5- A 2500g object is pushed with 55N for 12m in 11s, there was a force of friction of 30N.

Assoli18 [71]

Answer:

1kg =1000g

2.5kg

D=12m

t=11s

F=2.5KG

Explanation:

work done =f.d

=2.5×12

=30Nm

55-30

average speed

final - initial

divide by time t(s)

3 0

2 years ago

Copernicus incorrectly assumed that the planets?

hammer [34]

Nicholas Copernicus correctly assumed that the planets revolved around the sun but he incorrectly assumed that the planets followed a perfect circle orbit around the sun. It was later on discovered by Johannes Kepler that the planets moved around the sun following an elliptical orbit.

6 0

3 years ago