Answer:
4.04 s
Explanation:
h = vi + 1/2 a t ^2
HERE h = 80 m , vi = 0 , a =9.81 m/s^2
80 = 0 + 1/2 × 9.81 × t ^2
80 = 4.905 t^2
t^2 = 80/4.905
t ^2 = 16.30988
t = square root of 16.30988
t = 4.0385 s
t = 4.04 s
The formula of density is given by
Density = Mass ÷ Volume
We have:
Mass = 1.989 × 10³⁰ kg
Volume =

=

km³
Density =

=1.13×10¹⁸ kg/km³
Converting 1.13 × 10¹⁸ kg/km³ to g/cm³
1.13 × 10¹⁸ kg = 1.13 × 10¹⁸ × 10³ = 1.13 × 10²¹ grams
1 km³ = 1 × 10⁶ cm³
(1.13 × 10²¹) ÷ 10⁶ = 1.13 × 10¹⁵ gr/cm³
Answer: Density 1.13 × 10¹⁵ gr/cm³
The speed of the pin after the elastic collision is 9 m/s east.
<h3>
Final speed of the pin</h3>
The final speed of the pin is calculated by applying the principle of conservation of linear momentum as follows;
m1u1 + mu2 = m1v1 + m2v2
where;
- m is the mass of the objects
- u is the initial speed of the objects
- v is the final speed of the objects
4(1.4) + 0.4(0) = 4(0.5) + 0.4v2
5.6 = 2 + 0.4v2
5.6 - 2 = 0.4v2
3.6 = 0.4v2
v2 = 3.6/0.4
v2 = 9 m/s
Thus, The speed of the pin after the elastic collision is 9 m/s east.
Learn more about linear momentum here: brainly.com/question/7538238
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Answer:
1.1 Two poles: North and South Poles.
1.2 - Staple pin - Nail - Tip of my phone charger - Metal keys - Cloth Hanger
1.3 - Wooden bed cot - Plastic pen - Game pad - Wooden shelf - Paper - A T-shirt
1.4 Yes
1.5 No
here we will use the torque balance about the knee joint
here we can say that

here torque due to weight is given as



now torque due to applied force of muscle


now by torque balance we will have


so here the magnitude of m will be 173 N