What is the final temperature when 50 g of water at 20°c is mixed with 75 g of water at 60°c

Consider a vertical elevator whose cabin has a total mass of 800 kg when fully loaded and 150 kg when empty. The weight of the e

Eddi Din [679]

Answer:

Part a)

$P = 4.71 \times 10^3 Watt$

Part b)

$P = 2.94 \times 10^3 W$

Part c)

$P = 9.4 \times 10^3 W$

Part d)

$P = 3.9 \times 10^3 W$

Explanation:

Part a)

When cabin is fully loaded and it is carried upwards at constant speed

then we will have

net tension force in the rope = mg

$T = (800)(9.81)$

$T = 7848 N$

now it is partially counterbalanced by 400 kg weight

so net extra force required

$F = 7848 - (400 \times 9.81)$

$F = 3924 N$

now power required is given as

$P = Fv$

$P = 3924 (1.2)$

$P = 4.71 \times 10^3 Watt$

Part b)

When empty cabin is descending down with constant speed

so in that case the force balance is given as

$F + (150 \times 9.8) = (400 \times 9.8)$

$F = 2450 N$

now power required is

$P = F.v$

$P = (2450)(1.2)$

$P = 2.94 \times 10^3 W$

Part c)

If no counter weight is used here then for part a)

$F = 7848 N$

now power required is

$P = F.v$

$P = 7848 (1.2)$

$P = 9.4 \times 10^3 W$

Part d)

Now in part b) if friction force of 800 N act in opposite direction

then we have

$F + (150 \times 9.8) = 800 +(400 \times 9.8)$

$F = 3250 N$

now power is

$P = (3250)(1.2)$

$P = 3.9 \times 10^3 W$

3 0

2 years ago

A uniform metre rule of mass 10g is balanced on a knife edge placed at 45cm mark. Calculate the distance of a mass 25g from the

Verdich [7]

Answer:

The distance of a mass 25g from the pivot is 18cm

Explanation:

Given

$m_1 = 10g$

$d_1 = 45cm$

$m_2 = 25g$

Required

Distance of m2 from the pivot

To do this, we make use of:

$m_1 * d_1 = m_2 * d_2$ --- moments of the masses

So, we have:

$10 * 45= 25* d_2$

$450= 25* d_2$

Divide both sides by 25

$18= d_2$

Hence:

$d_2 = 18$

5 0

2 years ago

Energy that a microwave use to heat food?

yanalaym [24]

Electromagnetic energy

6 0

2 years ago

A bucket of water is being raised from a well using a rope. If the bucket of water has a mass of 6.2 kg, how much force (in N) m

Sholpan [36]

Answer:

6.2N force

Explanation:

According to Newton's second law of motion, force is equal to the product of the mass of a body and its acceleration. Mathematically,

Force = mass × acceleration

Given mass of bucket of water = 6.2kg

acceleration of the bucket = 1m/s²

Force exerted on the rope = 6.2 × 1

= 6.2N

5 0

2 years ago

A cyclist rides 6.2 km east, then 9.28 km in a direction 27.27 degrees west of north, then 7.99 km west. A. What is the magnitud

Pani-rosa [81]

Answer:

Explanation:

given,

cyclist ride 6.2 km east and then 9.28 km in the direction of 27.27° west of north and then 7.99 km west.

vertical component = 9.28 cos∅

= 9.28 cos 27.27°

= 8.24 km

horizontal axis component = 9.28 sin ∅

= 9.28 sin 27.27°

= 4.5 km

distance of the final point from the origin

= 7.99 -(6.2-4.5)

= 6.29 km

displacement

$d = \sqrt{6.29^2+8.24^2}$

d = 10.37 km

b) $tan \theta = \dfrac{6.29}{8.24}$

θ = 37.36°

4 0

2 years ago