**Answer:**

The mass of the lead will be "**1.127 kg**".

**Explanation:**

The given values are:

(Ice) m₁ = 50 g i.e.,

**0.050 kg**

(Water) m₂ = 195 g i.e.,

**0.190 kg**

(Copper cup) m₃ = 100 g i.e.,

**0.100 kg**

m₁, m₂ and m₃ at temperature,

**t₁ = 0°C**

Temperature of lead,

**t₂ = 96°C**

Temperature of Final equilibrium,

**t₃ = 12°C**

Let m₄ be the mass of the lead.

**On applying formula, we get**

⇒

**On putting the estimated values, we get**

⇒

⇒

⇒

⇒

⇒

**Answer:**

**amount of energy = 4730.4 kWh/yr**

**amount of money = 520.34 per year **

**payback period = 0.188 year**

**Explanation:**

given data

light fixtures = 6

lamp = 4

power = 60 W

average use = 3 h a day

price of electricity = $0.11/kWh

to find out

the amount of energy and money that will be saved and simple payback period if the purchase price of the sensor is $32 and it takes 1 h to install it at a cost of $66

solution

we find energy saving by difference in time the light were

ΔE = no of fixture × number of lamp × power of each lamp × Δt

ΔE is amount of energy save and Δt is time difference

so

ΔE = 6 × 4 × 365 ( 12 - 9 )

**ΔE = 4730.4 kWh/yr**

and

money saving find out by energy saving and unit cost that i s

ΔM = ΔE × Munit

ΔM = 4730.4 × 0.11

**ΔM = 520.34 per year **

and

payback period is calculate as

payback period =

payback period =

**payback period = 0.188 year**

**Explanation:**

The forces acting on a massless object (spring, hook, string or wire, if considered massless) will always balance. Balanced forces acting on an object cause it to compress or stretch. The forces acting on a mass will never cancel.

A ball would be something that floats in warter

**Answer:**

its a

**Explanation:**

because spheres dont really have a magnetic force